Listening to the sound of sentences

Although intonation conveys a great deal of information relevant to understanding sentences, it is unknown how listeners actually use this information. How do listeners integrate information in the intonation of a sentence with information derived from a linguistic analysis of the words in the sentence? Syntactic information from the order of words in a sentence may be processed independently from syntactic information perceived from intonation. On the other hand, different sources of syntactic information may be treated as equivalent and integral. Subjects were instructed to judge whether the intonation of a sentence was declarative or interrogative. Statements and questions were produced in two forms; with a declarative intonation and with an interrogative intonation. In one condition, syntactic structure was constant for all trials and intonation varied. In a second condition, syntactic structure varied across trials, as did intonation. The results indicate that listeners are unable to ignore the syntactic structure of a sentence in judging the intonation of the sentence. Listeners treat different types of syntactic information as integral. These results suggest that perception of intonation is a direct and integral part of sentence understanding. [Research supported by NIDCD.]